Grenco Marine Reaches Final for the Dutch Maritime Innovation Award
14 October 2005
Grenco Marine Innovation nominated for the Dutch Maritime Innovation Award.
Grenco Marine reached the final of the Dutch Maritime Innovation award with two other companies out of total of 20 companies that applied for the contest. The first of November the price will be awarded to one of the last three remaining companies by the Dutch Minister Mrs. Peijs on the first day of the EUROPORT MARITIME exhibition in Rotterdam, the Netherlands. In order to win the price, Grenco Marine applied with one of its latest developments in the refrigeration Technology which is their new NH3 / CO2 cascade system total screw compressor concept.
The basis reason for the development is caused by the fact that in many European countries the use of R22 in new refrigeration systems is prohibited. After 2010 charging of existing installations with newly produced R22 will not be allowed anymore in Europe. Within the present legislation, the choice can be made for, so called HFC's, such as R404A and R507, as replacement for R22. Alternative refrigerants like R507 and R404A are subject to very strict legislation and are bound to be prohibited in the nearby future as well, which will be the case in Denmark from the 1st of January, 2006.
By exclusive use of natural refrigerants in new installations, problems to comply with changing legislation can be prevented and fleet owners will not be confronted with additional investments for the adaptation of their refrigeration systems as a result of changing legislation.
Grenco offers a good solution for this problem by the development of a new NH3 / CO2 cascade system by which the use of chemical refrigerants can be avoided. Various Dutch and Norwegian fleet owners have chosen for a refrigeration system with environmentally friendly refrigerants, such as ammonia (NH3) and carbon dioxide (CO2). Moreover, these natural refrigerants have very good thermodynamic properties. CO2 has a high pressure (6,8bar at -50°C and 39,7 bar at 0°C), and it is therefore required to install a primary cooling system with another refrigerant (e.g. NH3) in order to keep the CO2 pressure within limits in the secondary system. NH3 is the preferred choice by many fleet owners, as the C.O.P. (Coefficient Of Performance) is approximately 25% better than R507 or R404A.
Innovation
Considerable product developments, for many components, were required, because of the higher pressures in the system. The screw compressor units of Grenco are especially developed for CO2, and new solutions had to be found for defrosting the plate freezers which is done with hot gas of the compressors. To make this possible the screw compressors had to be designed for higher discharge pressures and differential pressures.
Experiences on board of the Dirk-Dirk (trawler with a freezing capacity of 235 tons fish a day) show that Grenco was very successful with the development of the new system. With the installation aboard of the Dirk-Dirk, Grenco Marine is the first company in the world installing a NH3 / CO2 total screw compressor cascade system on board of a fishing vessel.
The benefits of freezing with CO2 are:
- The energy saving by applying natural refrigerants (NH3 and CO2) is substantial and amounts to 22% with respect to cooling systems with HFC's
- A total greenhouse gas emission reduction (TEWI reduction) is realized, from 70 until more than 90%, by reduction of the direct emissions
- 25% reduction of the freezing time
- Less freezing equipment
- Safe and natural refrigerants
- World wide available
- Cheap refrigerants
